guest: i have thought about it quite a bit. we have been trying to figure out how to do better on the diagnostic side of mental illness. it is clear that as long as we base our diagnoses on behavior, as i just said, we are getting there late. the question is how to bring biology and a number of other kinds of measures to the table so that we can identify these disorders much earlier and began to intervene much earlier with much better outcomes. if you listened to my colleagues who have been on the show this morning, it is really interesting how, across-the- board, whether talking about infectious diseases, cancer, we do not talk about heart disease but it is even more true there the lesson we learned in medicine is the earlier we can intervene, the better the outcomes. when you diagnose as dsm does, simply by presenting symptoms, you are always getting there late.